IIRC you need to have the BA Amex card to pay the taxes for the 241 (and you definitely need to pay using some form of Amex card) therefore cancellation prior to booking the flight may not be an option.
Also, 45,000 miles have a decent monetary value. You could fly Club Europe (from London, so you'd need to get down there from Birmingham) to the south of Spain (Malaga) - it won't be boiling hot but hotter than the UK!